Fluid absorption and distribution enhancement systems

ABSTRACT

Embodiments of a fluid absorption and distribution enhancement (FADE) product comprises at least one flow media layer, and at least one superabsorbent polymer layer.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.13/834,239 filed Mar. 15, 2013, which claims priority to U.S.Provisional Application Ser. No. 61/758,524 filed Jan. 30, 2013, whichis incorporated by reference herein in its entirety.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

This invention was made with U.S. Government support under Contract No.W81XWH-10-C-0193 awarded by the United States Army Medical Research andMaterial Command to Cornerstone Research Group Inc. The U.S. Governmenthas certain rights in the invention.

BACKGROUND

Patients being transported with significant injuries can expose thetransport equipment and caregivers to copious amounts of body fluids,e.g., urine, blood, feces, etc. Therefore, management of these fluids isimportant for proper patient treatment, reduced infection, and easierdecontamination. Additionally, for long term transport scenarios, itreduces the likelihood of pressure ulcer development.

Conventional products have utilized superabsorbent polymers to absorbthese body fluids; however, conventional products encounter variousdeficiencies and limitations, such as gel blocking due to engorgedsuperabsorbent polymers, poor absorbency under load, poor fluiddistribution across the superabsorbent polymer, slow absorption ratesand poor absorption capacity, as well as an inability to meetdimensional constraints and maintain the structural integrity of thesuperabsorbent polymer.

Regarding dimensional constraints, conventional products fail to achievegood fluid distribution to all regions of an absorbent pad. Therefore,these products compensate by adding more superabsorbent polymer materialmaking the end product thicker or bulkier. This is undesirable in manyapplications such as adult diapers where discretion is important. Inthese applications, wherein the product is thicker than desired becauseof poor fluid distribution, gel blocking, and absorption under loadissues. Moreover, structural integrity of the envelope or containmentpouch for the absorbent pad can rupture due to excessively engorgedsuperabsorbent polymer in regions that have poor fluid distribution.

SUMMARY

Accordingly, the present inventors have developed a new fluid managementsystem (hereinafter “fluid absorption and distribution enhancementproduct” or FADE product) to achieve improved fluid management,especially for conventional patient transport litters, stretchers,hospital beds, or ambulance cots. In addition to absorption of bodyfluids, non-body fluids, for example, fluids used for patient treatment(e.g., sterile water used for irrigating burn wounds). Referring to theembodiment of FIGS. 1 and 2, the present FADE product 5 (shown in FIG.2) can underlie a conventional mattress 2, for example a mattress usedon a patient support litter. As shown in FIG. 1, the mattress 2 includesdrainage slots 10 which act as flow channels for bodily fluids to passthrough the mattress 2. As shown in FIG. 2, the present FADE product mayinclude drainage channels 12 configured to align with the drainage slots10 when disposed under the mattress of FIG. 1. In operation, bodilyfluids will travel through the drainage slots and be collected andabsorbed within the present FADE product, which includes a system offlow channels and adsorbent materials. The present FADE product may be adisposable layered pad comprised of wicking and adsorbent materialsdeveloped for bulk fluid trapping and removal. While the present fluidabsorption product is useable with any conventional mattress, it iscontemplated that a mattress could be optimized as well to provideimproved channeling for drainage and fluid management in conjunctionwith the present fluid absorption product.

Without being limited by theory, the present FADE product has theability to drain, channel, and evenly disperse bodily fluid under a loadforce or under vacuum while preventing gel blocking at the fluidintroduction location, which is prevalent in superabsorbent polymerapplications.

While many of the embodiments discussed herein are focused on patienttransport litters, stretchers, hospital beds, or ambulance cots, thepresent fluid absorption product is suitable generally for use inabsorption pads (for example, absorption pads for the medical, pet, andfood industries), medical dressings, diapers, and any other applicationwhere fluid distribution and/or absorption is desired.

Without being bound by theory, the present FADE product achievesnumerous benefits. For example, and not by way of limitation, thesebenefits include: significantly accelerated fluid absorption time;uniform distribution of fluid across absorbent pad; avoidance ofgel-blocking of the absorbent pad which inhibits fluid absorption;maximized use of the superabsorbent polymer material; ultrathinembodiment and dimensional control options; flow potential againstgravity; significantly greater absorbance under load; an increasedability to deal with subsequent insults or incidents yielding increasedbodily fluid; and anti-shear properties that allow movement within thepad instead of translating into the patient's soft tissue.

In accordance with one embodiment, the FADE product comprises at leastone flow media layer forming a flow network of pathways to convey afluid disposed therein, and at least one superabsorbent polymer layeroriented above or below the at least one flow media layer.

Alternatively, a FADE product with a single flow media layer is alsopossible, wherein the superabsorbent polymer layer comprises flowchannels, and at least one superabsorbent polymer layer disposed belowthe flow media layer (See FIG. 4), or above the flow media layer (SeeFIG. 5).

In accordance with another embodiment, the FADE product comprises atleast two flow media layers and at least one superabsorbent polymerlayer comprising one or more flow channels sandwiched between the flowmedia layers. The flow media layers comprise woven material, non-wovenmaterial, pressed mesh, knitted mesh, scrim material, or combinationsthereof formed from nylon, polypropylene, propylene ethylene copolymer,polyolefin, polyester, polyamide, polyvinyl chloride, polyurethane, orcombinations thereof. The superabsorbent polymer layer comprises poly(sodium acrylate) homopolymer or copolymer, polyacrylamide copolymer,ethylene maleic anhydride copolymer, polyvinyl alcohol copolymers,polyethylene oxide, polyacrylonitrile copolymer, cross-linkedcarboxymethylcellulose, or combinations thereof.

In accordance with yet another embodiment, the FADE product comprises atleast three flow media layers including an upper flow media layer, amiddle flow media layer, and a lower flow media layer, and at least twosuperabsorbent polymer layers comprising a first superabsorbent polymerlayer disposed between the upper flow media layer and the middle flowmedia layer, and a second superabsorbent layer disposed between themiddle flow media layer and the lower flow media layer. The flow medialayers comprise woven material, non-woven material, pressed mesh,knitted mesh, scrim material, or combinations thereof formed from nylon,polypropylene, propylene ethylene copolymer, polyolefin, polyester,polyamide, polyvinyl chloride, polyurethane, or combinations thereof.The superabsorbent polymer layers comprises poly (sodium acrylate)homopolymer or copolymer, polyacrylamide copolymer, ethylene maleicanhydride copolymer, polyvinyl alcohol copolymers, polyethylene oxide,polyacrylonitrile copolymer, cross-linked carboxymethylcellulose, orcombinations thereof.

These and additional features provided by the embodiments of the presentdisclosure will be more fully understood in view of the followingdetailed description, in conjunction with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The following detailed description of specific embodiments of thepresent disclosure can be best understood when read in conjunction withthe drawings enclosed herewith.

FIG. 1 is a schematic of a patient support litter including fluiddrainage cutouts.

FIG. 2 is a schematic of the present fluid absorption and distributionenhancement product according to one or more embodiments of the presentinvention.

FIG. 3 is a schematic view of a commercial fluid absorption producthaving a single superabsorbent polymer layer.

FIG. 4 is a schematic view of a fluid absorption and distributionenhancement product having a channeled single superabsorbent polymerlayer and a flow media layer thereon according to one or moreembodiments of the present invention.

FIG. 5 is a schematic view of another fluid absorption and distributionenhancement product having a channeled single superabsorbent polymerlayer and a flow media layer disposed below the channeled singlesuperabsorbent polymer according to one or more embodiments of thepresent invention.

FIG. 6 is a schematic view of a multi-layer fluid absorption anddistribution enhancement product according to one or more embodiments ofthe present invention.

FIG. 7 is a schematic view of a multi-layer fluid absorption anddistribution enhancement product having flow channels in multiplesuperabsorbent layers according to one or more embodiments of thepresent invention.

FIG. 8 is a schematic view of a multi-layer fluid absorption anddistribution enhancement product having flow channels in onesuperabsorbent layer according to one or more embodiments of the presentinvention.

FIG. 9 is a schematic view illustrating bulk fluid channeling accordingto one or more embodiments of the present invention.

The embodiments set forth in the drawings are illustrative in nature andnot intended to be limiting of the invention defined by the claims.Moreover, individual features of the drawings will be more fullyapparent and understood in view of the detailed description.

DETAILED DESCRIPTION

Referring to FIGS. 4-8, various embodiments of a fluid absorption anddistribution enhancement (FADE) product 5 are provided. Referring toFIGS. 4 and 5, a FADE product 5 may comprise at least one flow medialayer 50, and at least one superabsorbent polymer layer 20 orientedabove (FIG. 4) or below (FIG. 5) the flow media layer 50, wherein theone superabsorbent polymer layer 20 includes flow channels 25 thereinwhich assists in the lateral distribution of fluid as shownschematically in FIG. 9. Referring to FIG. 6, the FADE product 5 maycomprise at least two flow media layers 50, and at least onesuperabsorbent polymer layer 20 sandwiched between flow media layers oradjacent flow media layer.

The ability to use multiple layers dramatically improves fluidchanneling and accelerates the fluid absorption time allowing for moreeven fluid distribution; however, improvements in fluid distribution areachievable with various structures as well as structural modifications.For example, achieving slower or faster superabsorbent polymerabsorption rates at specific layers and locations of the FADE productmay be tailored by varying the layer structure as well as the channelingand drainage within the layers. Suitable contemplated structures mayinclude, for example and not by way of limitation, single or multiplesuperabsorbent polymer layers, single or multiple flow media layersdisposed above and/or below the superabsorbent polymer layers, andoptionally superabsorbent fiber materials. As used herein“superabsorbent fiber materials” means including superabsorbent polymerin a woven or non-woven fiber structure. Various additional structuresarte contemplated herein, for example merely doping superabsorbentpolymer onto a suitable sheet, carrier, or substrate. It is furthercontemplated that superabsorbent fibers may replace flow media or beused in conjunction with flow media layers.

As shown in FIGS. 4-8, the FADE product 5 may also comprise a coverlayer 30. In one exemplary embodiment, the cover layer 30 comprisesnonwoven mesh. Moreover as shown in FIGS. 4-8, the FADE product 5 mayfurther comprise a backing layer 40, for example, a clear backing layer.Various additional compositions are contemplated for the cover layer 30and backing layer 40, and it is noted that one or both of these layersis optional depending on the industrial application.

Flow media layer 50 options are vast in design, material, and dimension.For example, there are stretchy materials, varied thicknesses,coarseness, planer, and egg crate concepts that can be conceivedfollowing a review of currently available flow media and desiredperformance requirements. Specific tailorable performance featuresinclude the use of non-uniform, non-traditional weaves or interlacingthat creates a specific flow network or pattern. Similar to thecirculatory system of the human body that is comprised of arteries,arterioles, and capillaries, a network of larger to smaller channels canbe created through the use of thicker material in areas wheresignificant flow is desired. These larger pathways will quickly guidefluid to the smaller channels to allow for collection in the desiredabsorption zones of the pad.

In specific embodiments, the flow media layers 50 may be layerscomprised of woven material such as Style 6781 S2-Glass fabric fromFibre Glast, or non-woven materials. Examples of non-woven materialsthat can be used as flow media layers are knit material e.g.Breatherflow 60 from Airtech, pressed directional materials, such asResinflow 60 from Airtech, random mats, such as Continuous Strand Matfrom Fibre Glast, as well as other mesh or scrim material, orcombinations thereof. Another commercially suitable embodiment is theGREENFLOW 75 produced by Airtech Advanced Materials Group. Variouscompositions are contemplated for use in the woven or non-wovenstructures. For example, the flow media layers 50 may comprise nylon,polypropylene, propylene ethylene copolymer, or combinations thereof.Moreover, the flow media layers may comprise at least about 25%, or atleast about 50% by weight of nylon, polypropylene, propylene ethylenecopolymer, or both.

In an additional embodiment, the FADE product 5 may comprise at leasttwo flow media layers 50 in contact with one another. Without beingbound by theory, pressure, temperature, moisture, and shear allcontribute to the formation of pressure ulcers for the patient. Studiesshow that bed sores are caused by friction and shear forces generatedfrom movement of soft tissue around a bony contact area. To combat thisshear effect, the FADE product may use two layers of flow layer mediamesh in contact with one another to create a “slip sheet” allowing theabsorption pad to stretch and move, instead of the patient's softtissue, thereby reducing the likelihood of pressure ulcer development.It is contemplated that the same flow media layer compositions may bedisposed in contact or different flow media layer compositions may bestacked.

As shown in FIGS. 4-8, these flow media layers 50 are porous structures,which may optionally include channels that encourage lateral fluid flowacross the surface of the superabsorbent polymer layer 20. As shown inFIGS. 2, 4, and 6-8, the superabsorbent polymer layers 20 may compriseflow channels 25 extending through the superabsorbent polymer layers 20which also encourage lateral fluid flow.

Referring to the embodiment of FIGS. 5-8, the superabsorbent polymerlayer 20 may be disposed between two flow media layers 50. Variouscompositions are contemplated for use as a superabsorbent polymer layer20. For example, the superabsorbent polymer layer 20 may comprise poly(sodium acrylate) homopolymers or copolymers, polyacrylamide copolymers,ethylene maleic anhydride copolymers, polyvinyl alcohol copolymers,polyethylene oxides, polyacrylonitrile copolymers, cross-linkedcarboxymethylcellulose, or combinations thereof. In one exemplaryembodiment, the superabsorbent polymer layer 20 comprises poly (sodiumacrylate) homopolymer. Commercially suitable embodiments may include theULTRABLEND 345 produced by Gelok International Corp. Various structuralconfigurations are contemplated for the superabsorbent polymer layer.For example as shown in FIG. 3, the superabsorbent polymer core layer 20may comprise a cover layer 30 on top of the superabsorbent core layer20, and a backsheet layer 40 disposed underneath the superabsorbent corelayer 20.

In further embodiments, the superabsorbent polymer layer 20 may includeflow channels 25, for example, in one or more of the superabsorbentpolymer layers 20 of a multi-layer FADE product 5. Specificallyreferring to FIGS. 7 and 8 in conjunction with FIGS. 1 and 2, these flowchannels 25 may be designed cut-out areas in one or both of thesuperabsorbent polymer layers 20 which may be aligned with drainageslots 10 or “through holes” in the mattress 2 to further increase thez-direction flow in those areas where large amounts of fluids would beintroduced to the absorbent pad and tend to pool. The ability to allowfluid movement in the z-direction as shown in FIGS. 4-8, perpendicularto the superabsorbent polymer layer 20 surface, dramatically improvesfluid absorption time, provides for better fluid distribution, and canprevent gel blocking. While FIGS. 7 and 8 both show embodiments wherethe top or upper superabsorbent polymer layer includes flow channels 25,it is contemplated in further embodiments to only include flow channelsin a lower superabsorbent polymer layer. Moreover, it is contemplatedthat the layers of the structure could be rearranged, so thatsuperabsorbent polymer layers are in direct contact or the flow medialayers are in direct contact.

Additionally, the FADE product 5 may comprise deionizing material or adeionizing coating. Constructing the flow media layers 30 with adeionizing material or applying a deionizing coating onto thesuperabsorbent polymer layer 20 can increase absorption rate ascomparing to the absorption rate of ionized body fluids. Selectivelyemploying this concept can create targeted absorption areas that can belocated anywhere in the absorbent field. Without being bound by theory,keeping absorption low near the areas of fluid introduction will allowfor multiple uses which is a desired feature of superabsorbent polymerpads for patients.

In yet another embodiment, the superabsorbent polymer layer 20 maycomprise small slits configured to facilitate stretching. Without beinglimited to a specific method of making, the small slits may be laseretched into the superabsorbent polymer layer. Alternatively, thesuperabsorbent polymer layer may be a structure wherein superabsorbentpolymer is impregnated into a stretchable fabric layer Like theanti-shear slip sheet embodiment, the stretchability of thesuperabsorbent polymer achieved by a superabsorbent polymer impregnatedinto a stretchable fabric layer may aid in the reduction of pressureulcers.

In one advantageous embodiment, the fluid absorption and distributionenhancement product achieves excellent fluid distribution under load. Asnoted above, a pressure applied to absorbent pads can impede the fluidwicking and distribution and lead to fluid pooling in specific areas.This can lead to poor absorbency. Consequently, the present fluidabsorption and distribution enhancement product enhances fluidabsorption in the superabsorbent polymer layer by distributing fluidsthrough the flow media layers, and optionally may further enhance fluidabsorption by including flow channels in one of the superabsorbentpolymers layers, for example, in an upper superabsorbent polymer layerto allow lateral distribution of fluid into the lower superabsorbentpolymer layer.

EXAMPLES

The present inventors performed comparative experiments to demonstratethat fluid absorption and distribution. The evaluations were conductedwith 250 ml of saline solution 0.9% introduced through an acryliccylinder. Absorption under load (AUL) scenarios included uniform loadingusing steel plates that imparted 0.15 psi on the pad surface. These AULscenarios are used to simulate the compression created by body weight onthe pad.

The starting sheet was the conventional commercial product of FIG. 3.Water and blood simulant (0.9% saline solution) were both quicklyabsorbed, when no load was applied.

That being said, applying pressure to the sheet of FIG. 3 impeded theability of the sheet to absorb fluid, and fluid pool was formed.Applying pressure resulted in areas of fluid pooling as it could notwick nor absorb into the superabsorbent polymer layer. Incorporating aflow media layer 50 above the absorbent polymer 20 with flow channels 25as shown in FIG. 4 greatly increased the wicking ability of the productand improved fluid absorption even when pressure was applied.

Incorporating two layers of superabsorbent polymer with flow media meshlayers in between resulted in improved wicking and shared absorption offluid as shown in FIG. 6. Additionally, each superabsorbent polymerlayer absorbed roughly equal quantities of the fluid.

Moreover, the FIG. 8 design incorporates two superabsorbent polymerlayers 20 sandwiched between three nylon flow media layers 50.Additionally, flow channels 25 are present in the top absorbent polymerlayer corresponding to drainage slots or “through holes” in a mattressto further increase the wicking ability in those areas where largeamounts of fluids would be introduced to the absorbent pad and tend topool. These two modifications resulted in vastly superior absorbencyperformance in the AUL demonstration. In the demonstration, the modifiedabsorbent pad exhibited both full absorption and even distribution ofthe fluid underneath the load plates in approximately one-third of thetime it took a conventional pad as shown in FIG. 3 to absorb the sameamount of fluid with no load at all as shown in FIG. 8.

The use of the FADE product highlighted the following performancecharacteristics: accelerated absorption rates; significantly moreuniform fluid distribution and absorption; balanced drainage andchanneling capabilities; and absorption under load that was nearly threetimes faster than superabsorbent polymer that was not under load.

It is further noted that terms like “preferably,” “generally,”“commonly,” and “typically” are not utilized herein to limit the scopeof the claimed invention or to imply that certain features are critical,essential, or even important to the structure or function of the claimedinvention. Rather, these terms are merely intended to highlightalternative or additional features that may or may not be utilized in aparticular embodiment of the present disclosure.

It will be apparent that modifications and variations are possiblewithout departing from the scope of the disclosure defined in theappended claims. More specifically, although some aspects of the presentdisclosure are identified herein as preferred or particularlyadvantageous, it is contemplated that the present disclosure is notnecessarily limited to these aspects.

What is claimed is:
 1. A fluid absorption and distribution enhancement(FADE) product comprising: at least one flow media layer forming a flownetwork of pathways to convey a fluid disposed therein; and at least onesuperabsorbent polymer layer oriented above or below the at least oneflow media layer.
 2. The FADE product of claim 1 where the FADE productis integrated into an absorption pad for use in the medical, pet, orfood industries.
 3. The FADE product of claim 1 where the FADE productis integrated into a medical dressing.
 4. The FADE product of claim 1where the FADE product is integrated into a diaper.
 5. The FADE productof claim 1 where the FADE product is integrated into a hospital bed. 6.The FADE product of claim 1 where the FADE product is integrated into anambulance cot.
 7. The FADE product of claim 1 where the FADE product isintegrated into a patient transport litter.
 8. The FADE product of claim1 further comprising one or more flow channels in the superabsorbentpolymer layer.
 9. The FADE product of claim 1 further comprisingsuperabsorbent fiber material.
 10. The FADE product of claim 1 furthercomprising at least two flow media layers in contact with one another.11. The FADE product of claim 1 further comprising deionizing materialor a deionizing coating.
 12. The FADE product of claim 1 where thesuperabsorbent polymer layer comprises small slits configured tofacilitate stretching.
 13. The FADE product of claim 1 where thesuperabsorbent polymer layer comprises superabsorbent polymerimpregnated into a stretchable fabric layer.
 14. The FADE product ofclaim 1 where the FADE product comprises at least three flow medialayers including an upper flow media layer, a middle flow media layer,and a lower flow media layer; and at least two superabsorbent polymerlayers comprising a first superabsorbent polymer layer disposed betweenthe upper flow media layer and the middle flow media layer, and a secondsuperabsorbent layer disposed between the middle flow media layer andthe lower flow media layer, wherein the first superabsorbent polymerlayer, the second superabsorbent polymer layer, or both comprise one ormore flow channels.
 15. A fluid absorption and distribution enhancement(FADE) product comprising: at least two flow media layers; and at leastone superabsorbent polymer layer comprising one or more flow channelssandwiched between the flow media layers; wherein, the flow media layerscomprise woven material, non-woven material, pressed mesh, knitted mesh,scrim material, or combinations thereof formed from nylon,polypropylene, propylene ethylene copolymer, polyolefin, polyester,polyamide, polyvinyl chloride, polyurethane, or combinations thereof,and the superabsorbent polymer layer comprises poly (sodium acrylate)homopolymer or copolymer, polyacrylamide copolymer, ethylene maleicanhydride copolymer, polyvinyl alcohol copolymers, polyethylene oxide,polyacrylonitrile copolymer, cross-linked carboxymethylcellulose, orcombinations thereof.
 16. The FADE product of claim 15 where the FADEproduct comprises at least three flow media layers including an upperflow media layer, a middle flow media layer, and a lower flow medialayer; and at least two superabsorbent polymer layers comprising a firstsuperabsorbent polymer layer disposed between the upper flow media layerand the middle flow media layer, and a second superabsorbent layerdisposed between the middle flow media layer and the lower flow medialayer.
 17. The FADE product of claim 15 further comprising deionizingmaterial or a deionizing coating.
 18. The FADE product of claim 15 wherethe superabsorbent polymer layer comprises small slits configured tofacilitate stretching.
 19. The FADE product of claim 15 where thesuperabsorbent polymer layer comprises superabsorbent polymerimpregnated into a stretchable fabric layer.
 20. The FADE product ofclaim 15 where the FADE product is integrated into an absorption pad foruse in the medical, pet, or food industries.